1. Field of the Invention
The present invention relates generally to copper refining, and specifically to a system for continuously refining secondary and blister copper to produce and continuously cast anode grade copper.
2. Description of the Prior Art
Refining impure copper to produce anode grade copper is well known in the prior art. All known prior art refining has been batch refining usually by reverberatory furnaces such as those disclosed in U.S. Pat. Nos. 2,436,124, 3,664,828 and 3,614,079. The present invention, however, is a continuous process.
The system begins with continuous melting of copper in a vertical shaft furnace so that as molten copper continuously drains from the bottom of the furnace, new copper charge is continuously or semicontinuously added to the furnace to maintain constant melting of copper. Examples of vertical shaft furnaces are disclosed in U.S. Pat. Nos. 2,283,163, 3,199,977, 3,715,203 and 3,788,623, and in U.S. Patent application Ser. No. 921,039.
The molten copper continues through various processing vessels which refine and control the flow rate of the molten copper to an intermediate ladle which contains a ceramic foam molten copper filter such as the one disclosed in U.S. Pat. No. 4,277,281. The molten copper is then continuously cast into anodes of suitable quality for electrorefining or into a cast product not requiring electrorefining.
The present invention is higher in productivity, consumes less energy and causes less idle and downtime than conventional batch-type systems.